Hi Every time I up a VM with Xen 3.0.3 on CentOS 5.4 I get this messages on kernel: Apr 5 09:03:07 zebra kernel: BUG: warning at lib/kref.c:32/kref_get() (Not tainted) Apr 5 09:03:07 zebra kernel: Apr 5 09:03:07 zebra kernel: Call Trace: Apr 5 09:03:07 zebra kernel: [<ffffffff8023824d>] kref_get+0x38/0x3d Apr 5 09:03:07 zebra kernel: [<ffffffff8025a440>] kobject_get+0x12/0x17 Apr 5 09:03:07 zebra kernel: [<ffffffff8024b57f>] blk_get_queue+0x1f/0x26 Apr 5 09:03:07 zebra kernel: [<ffffffff887198f7>] :blkbk:dispatch_rw_block_io+0x4db/0x5a2 Apr 5 09:03:07 zebra kernel: [<ffffffff80340368>] __next_cpu+0x19/0x28 Apr 5 09:03:07 zebra kernel: [<ffffffff8026082b>] error_exit+0x0/0x6e Apr 5 09:03:07 zebra kernel: [<ffffffff8028792a>] find_busiest_group+0x1db/0x44d Apr 5 09:03:07 zebra kernel: [<ffffffff802883c0>] dequeue_task+0x18/0x37 Apr 5 09:03:07 zebra kernel: [<ffffffff80288407>] deactivate_task+0x28/0x5f Apr 5 09:03:07 zebra kernel: [<ffffffff8026ef47>] monotonic_clock+0x35/0x7b Apr 5 09:03:07 zebra kernel: [<ffffffff80262dd3>] thread_return+0x6c/0x113 Apr 5 09:03:07 zebra kernel: [<ffffffff80340af5>] kobject_cleanup+0x39/0x7e Apr 5 09:03:07 zebra kernel: [<ffffffff88719d2c>] :blkbk:blkif_schedule+0x36e/0x456 Apr 5 09:03:07 zebra kernel: [<ffffffff887199be>] :blkbk:blkif_schedule+0x0/0x456 Apr 5 09:03:07 zebra kernel: [<ffffffff8029bdab>] keventd_create_kthread+0x0/0xc4 Apr 5 09:03:07 zebra kernel: [<ffffffff80233bef>] kthread+0xfe/0x132 Apr 5 09:03:07 zebra kernel: [<ffffffff80260b2c>] child_rip+0xa/0x12 Apr 5 09:03:07 zebra kernel: [<ffffffff8029bdab>] keventd_create_kthread+0x0/0xc4 Somebody know what is going on???? Thanks for any help -- Gilberto Nunes